This invention relates generally to core pin assemblies for molding and die casting apparatus, and more particularly to a spring unit for a core pin assembly.
U.S. Pat. No. 3,161,918 discloses a core pin assembly for use in die casting and molding apparatus. That assembly provided a sleeve mounted in an opening extending from the parting surface of the mold section, the sleeve having a head engaging a shoulder in the opening thereby preventing movement of the sleeve in the direction toward the parting surface. The sleeve has a tapered bore which diverges toward the parting surface and a core pin having a mating taper is seated in that bore, the taper thus preventing movement of the core pin relative to the sleeve in the direction away from the parting surface. The core pin has an end extending beyond the head on the sleeve member. The opening has a bottom and a coil spring in the opening exerts force between the bottom and a washer which engages the head on the sleeve member thereby resisting movement of the sleeve member and a core pin in the direction away from the parting surface. An abutment pin is positioned within the spring with one end removably attached to the bottom of the opening by a screw and its other end normally closely spaced from the end of the core pin.
It is necessary on occasion to disassemble the core pin assembly and with the construction shown in the aforesaid U.S. Pat. No. 3,161,918, such disassembly resulted in a collection of separate parts including the washer, spring, abutment pin and screw, which easily could become lost. Further, re-assembly of the core pin assembly was time consuming and the assembly could be improperly reassembled.
It is therefore desirable to provide an improved core pin assembly which will alleviate the aforesaid problems encountered in the disassembly and re-assembly of the construction of the aforesaid U.S. Pat. No. 3,161,918.